C-reactive protein and depressed mood in a sub-group of smokers during nicotine abstinence.

Cigarette smokers frequently fail multiple attempts to quit smoking, often because of the unpleasant symptoms that accompany quitting. Similar unpleasant symptoms accompany inflammatory responses during infection and autoimmune disease. The hypothesis that smoking abstinence induces inflammation was tested. Eighteen smokers (n = 18) were evaluated while smoking freely and after 24 h of nicotine abstinence. Immune, cardiovascular and psychological measures were collected. Hunger, nervousness, anxiety, restlessness and irritability increased during abstinence (p < 0.05); systolic blood pressure and heart rate levels decreased (p < 0.05). Analysis demonstrated a split among smokers in response to abstinence compared with smoking freely; some smokers (n = 10) displayed increased C-reactive protein (CRP, p < 0.05) whereas others (n = 8) responded with decreased CRP (p < 0.05). An increase in symptoms of depressed mood and a fall in heart rate occurred only in those who displayed increased CRP with nicotine abstinence ( p < 0.05), while systolic blood pressure fell only in those whose CRP levels decreased with abstinence ( p < 0.05). Interleukin-1 and interleukin-6 did not change with abstinence. The results suggest that 24 h nicotine abstinence does not stimulate inflammation among all smokers, but that a sub-group of smokers do demonstrate an inflammatory response with significant negative psychological and physiological symptomatology.